Jean Baptiste was born 1763 in the city of Pau in southwest France. His parents were Henri Bernadotte and Jeanne Saint Jean (he was not royal by blood).
He enlisted in 1780 with the Royal-la-Marine regiment and when the social barriers were broken down by the French Revolution in 1789 his military career progressed quickly, in 1794 he had the position of Divisional General and he became later Minister of War. With the introduction of the First French Empire, Bernadotte became one of the eighteen Marshals of the Empire.
He married Désirée Clary in 1798 and their only child, Joseph François Oskar was born in Paris 1799. He also had an acknowledged daughter prior to marriage, Olympe Louise Catherine, born 1789.
In 1810 Bernadotte was about to enter a new post as governor of Rome when he was unexpectedly approached by a Swedish courtier who offered him the succession to the Swedish crown. In august the same year, Jean Baptiste was elected by the Riksdag of the Estates to be the new Crown Prince. He was adopted by King Charles XIII under the name of "Charles John" (Karl Johan).
In 1814 Sweden and Norway became the United Kingdoms of Sweden and Norway.
When King Charles XIII of Sweden died 1818, the Crown Prince was crowned King, first in Stockholm as King Charles XIV John av Sverige and then in Trondheim as King Charles III John of Norway. His motto as a King were: The love of the people - my reward.
During his long reign of 26 years, the national debt was paid off, a civil and a penal code were proposed for promulgation, education was promoted, agriculture, commerce, and manufactures prospered, and the means of domestic communication were improved. It is said that it was during his reign the origin of Swedish neutrality were born.
Having long enjoyed good physical and spiritual health, he suffered a stroke on his 81st birthday in 1844. Further complications ensued, and he died on 8 March at the Royal Palace of Stockholm. 
A state funeral was held on April 26 and he was buried in Stockholm's Riddarholm Church.
1763 jan 26 born in Pau, Béarn, France; baptised the following day. He was the son of Henri (de) Bernadotte, procurator to the Seneschal, and Jeanne Saint-Jean. His godparents were Jean Bernadotte, Junior ("cadet"), procurator to the seneschal, and Marie Betbeder his wife.
Olympe Louise Catherine, born on 4 August 1789 in Grenoble, was the daughter of Catherine Lamour and Jean Bernadotte, sergeant in the Royal Navy Regiment. She was baptised on the following day in Saint-Louis church in Grenoble.
She had been acknowledged through a declaration to Me Girard, notary, on 8 may 1789 (three months before the birth).
1798 On 30 Thermidor year VI (August 17, 1798) he married Bernardine Eugénie Désirée Clary in Sceaux, near Paris.
Their son Joseph François Oskar was born in July 1799 in Paris, France 
Note: Also King Karl III Johan of Norway. Was Marshal of France and Prince of Ponte-Corvo before he was elected Crown Prince of Sweden and adopted by King Carl XIII.
The son of a Pau lawyer made an astonishing rise to power. At a young age, Bernadotte first enlisted in the royal armies and then in the revolutionary armies. General by 1794, he left the Army of the Rhine to lend his support to Bonaparte in Italy in 1797. He was asked to take the enemy flags to the Directory. After a brief mission as ambassador to Vienna, he became minister of War under the Directory, from July to September 1799.
Bernadotte would never be an unwavering Bonaparte supporter. He refused to take part in the 18-Brumaire coup d'état, and thus earned the reputation of being a radical Jacobin. As commander of the Army of the West, his name was linked to what was called the "butter pot" conspiracy (since the anti-Bonaparte leaflets circulated in these pots). Then he married Désirée Clary, Bonaparte's ex-fiancée, thus becoming brother-in-law to Joseph Bonaparte, married to Julie Clary since 1794.
Nonetheless, he was named marshal in 1804 and prince of Pontecorvo two years later, even though he played a minor role in major battles. During the two simultaneous battles at Auerstädt and Jena, he was apparently long in bringing up reinforcements. Napoleon did not hold this against him, probably because of the Emperor's past relationship with Désirée Clary.
While pursuing the remains of the Prussian army after the battle, Bernadotte made contacts with Swedes taken prisoner at Lübeck. This proved to be an important step, since on August 21, 1810, undoubtedly because of the relations he had formed with the prisoners, he was elected crown prince of Sweden by the Öretro States General. The Swedes hoped to have a ruler who would have Napoleon's approval. The Emperor did not support Bernadotte but did not oppose him either. The new prince himself "became" completely Swedish: he renounced Catholicism and took the affairs of the kingdom to heart.
Some wondered if he would become a traitor. In 1812, he drew closer to Russia and entered a coalition against France in 1813. His army beat Oudinot at Grossberen and Ney at Dennewitz. Though he may have coveted the French throne as it was said he did not obtain it; however the Treaty of Kiel on January 14, 1814 granted him the throne of Norway. On February 5, 1818, he took the name Charles XIV, King of Sweden and Norway. The dynasty he founded still reigns in Sweden.
Prince of Ponte Corvo 5 of June 1805. Elected heir to the Swedish throne 21 of August 1810, adopted by King Carl XIII, Swedish Crown Prince 5 of November 1810, Norwegian Crown Prince 4 of November 1814. King of Sweden and Norway upon the death of Carl XIII. Crowned in Stockholm 11 of May and in the Cathedral of Trondheim 7 of September.
Motto: The people's love my reward
As King Carl XIV Johan he was the first monarch of the Bernadotte dynasty on the throne of the two countries. He never learnt to speak either Swedish or Norwegian, and was often in conflict with the Storting (parliament), not least in his repeated attempts to increase the power of the crown. More than anything else Carl Johan, as founder of the House of Bernadotte, wanted the union between Sweden and Norway to be a solid edifice, based on mutual trust and respect. He initiated the building of the Royal Palace in Oslo, and today the city's main street bears his name. With his queen, known as Desideria (Desirée Clary, Napoleon´s former fiancée, the daughter of a well-established merchant in Marseilles), he had one son, Oscar.
It may be possible to confirm family relationships with Karl XIV Johan by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Karl XIV Johan: